The need to detect environmental conditions or changes arises in many situations. For example, solid materials or liquids may be introduced into or collect within an environment, parts or components of a system may wear down or out, or the temperature, pressure, chemical composition, atmosphere and/or some other environmental condition may change. Regardless of whether such changes or conditions may be beneficial, benign, harmful, desirable and/or undesirable, an indication of the change or condition may be useful. However, such changes or conditions may occur in locations where access is difficult or even impossible, where access, although possible or even simple, is undesirable for any number of reasons, and/or where the environmental conditions or changes may be hazardous to humans and/or equipment.
Nonexclusive illustrative examples of such environmental conditions or changes may include detecting worn-out equipment or materials, detecting leaks in containers carrying a fluid, detecting the presence of fluids in undesirable locations, detecting leaching (leaks of chemicals) in silver or gold mining operations, detecting water or gas line bursts, or the like. Additional examples may include the detection of temperature changes, atmospheric changes (such as changes in pressure and/or composition), the presence or absence of one or more materials, and/or changes in other physical or environmental conditions such as light or noise levels, or wear of mechanical devices, such as brake pads or the like.
Additional nonexclusive illustrative examples of situations in which it would be desirable to detecting environmental conditions or changes arise in the field of health care. For example, the detection of body fluids would be desirable for assisting in the prevention of diaper rash, for potty training of infants, and in curing enuretic youngsters, as well as for detecting the leakage of blood or other fluids after surgery and invasive diagnostic procedures. As a further nonexclusive illustrative example, the detection of incontinence in chronically bedridden persons, such as in the elder care field, would be useful to facilitate better care for chronically bedridden persons.
For example, incontinence is a considerable problem in elder health care. Elders often are immobile, and if these immobile elders become incontinent and lose control of the evacuative functions of urination or defecation and soil themselves, they may be unable to help themselves or seek help. The urine or feces might stay in place long enough for the elder to develop sores, which can result in sickness, infection, and in the worse cases, even death.
The current method of determining whether an elder has lost control of his or her evacuative functions of urination or defecation requires a caregiver to manually check the elder's bedding and/or diaper. This is an arduous and demeaning process, both for the caregiver and for the elder. Thus, there exists a need for an easy and non-intrusive method of detecting incidents of incontinence in elders.
Examples of sensors or systems for detecting predetermined environmental conditions are disclosed in the following U.S. Pat. Nos. 5,557,263; 5,570,082; 5,904,671; 6,294,997; 6,373,395; 6,583,722; 6,774,800; 6,846,994; 6,916,968; 7,053,781; 7,071,830; and U.S. Patent Application Publication Nos. 2004/0061655; 2005/0012616; 2005/0285746. Examples of radio frequency identification (RFID) devices and systems are disclosed in the following U.S. Pat. Nos. 5,904,671; 6,294,997; 6,583,722; 6,774,800; 6,898,489; U.S. Patent Application Publication Nos. 2004/0061655; 2005/0012616; 2005/0285746; and in PCT Publication Nos. WO 99/16019; WO 01/80174; WO 2004/016454; WO 2004/046762; WO 2005/006243; WO 2005/025554; WO 2005/076205; WO 2005/109308. The complete disclosures of these and all other publications referenced herein are incorporated by reference in their entirety for all purposes.